This plan, confirmed by many reports, seemed to Cæsar full of prudence, and altogether contrary to the usual rashness of the barbarians. He took, therefore, every possible care to dissimulate the number of his troops; he had with him the 7th, 8th, and 9th legions, composed of old soldiers of tried valour, and the 11th, which, formed of picked young men who had gone through eight campaigns, deserved his confidence, although it could not be compared with the others with regard to bravery and experience in war. In order to deceive the enemies by showing them only three legions, the only number they were willing to fight, he placed the 7th, 8th, and 9th in one line; whilst the baggage, which was not very considerable, was placed behind, under the protection of the 11th legion, which closed the march. In this order, which formed almost a square, he came unawares in sight of the Bellovaci. At the unexpected view of the legions, which advanced in order of battle and with a firm step, they lost their courage; and instead of attacking, as they had engaged to do, they confined themselves to drawing themselves up before their camp, without leaving the height. A valley, deeper than it was wide (_magis in altitudinem depressa quam late patente_), separated the two armies. On account of this obstacle and the numerical superiority of the barbarians, Cæsar, though he had wished for battle, abandoned the idea of attacking them, and placed his camp opposite that of the Gauls, in a strong position (the camp of Saint Pierre-en-Chatre [_in Castris_], in the forest of Compiègne).[543] (_See Plates 29 and 30._) He caused it to be surrounded with a parapet twelve feet high, surmounted with accessory works, proportioned to the importance of the retrenchment (_loriculamque pro ratione ejus altitudinis_),[544] and preceded by a double fosse, fifteen feet wide, with a square bottom;[545] towers of three stories were constructed from distance to distance, and united together by covered bridges, the exterior part of which was protected by hurdle-work. In this manner, the camp was protected not only by a double fosse, but also by a double row of defenders, some of whom, placed on the bridges, could, from this elevated and sheltered position, throw their missiles farther and with a better aim; while the others, placed on the _vallum_, nearer to the enemy, were protected by the bridges from the missiles which showered down upon them. The entrances were defended by means of higher towers, and were closed with gates.